HEATMOS: High Temperature HEPA Filter. Created to meet the highest demands under extreme conditions

Several characteristic requirements for high temperature HEPA filters can be identified that directly influence the productivity of a sterilization tunnel. From various in-depth interviews and tests conducted with renown tunnel manufacturers and pharmaceutical end users, two HEPA filter requirements have been found most critical in especially the hot zone of a sterilization tunnel:

1. High stiffness and durability of construction; 
2. Proven efficiency performance during operation.

Historically seen, the number of options available to tunnel manufacturers and pharmaceutical end users for HEPA filters that can withstand temperatures up to 350 °C has been limited.

The latest development step to date is the innovation to AAF International’s HEATMOS filter design which facilitates the filter efficiency H14 with improved air throughput, while at the same time being capable of allowing high heating rates, ensuring highest cleanliness demands and shortest possible process times.

The HEATMOS is designed with stainless steel housing and a sophisticated separator technology of corrugated stainless steel sheets positioned in an staggered fashion, which allows most even air passage while avoiding detrimental compression of the filter medium.

The innovative step is to seal the pleat pack of the filter to the frame with a new type of mechanically flexible glass-fiber-wool-ceramic composite material that enables a completely leak-free design over the duration of hundreds of operating cycles.

The use of a high-technology glass fiber-based filter medium meets the enormous requirements of the filter class H14 at high temperatures and astoundingly low pressure loss.

The entire frame construction is designed to provide a maximum possible mechanical strength as to resist the expansion and contraction forces that occur during the thermal application process. This ensures perfect dimensional stability for the safety of the fragile filter media package and for safe and leak-free coupling of the filter to the equipment.

The novel design of the HEATMOS filter offers the highest quality standard and ensures fulfillment of all technical specifications and requirements as stated by the guidelines of both, FDA regulation 21 CFR-211.94, and EU-GMP Annex 1.

HEATMOS filters of certified H14 filter efficiency were tested at globally renown sterile tunnel manufacturers on site. Operating temperatures were up to 350 °C continuously.

During multiple tests for all three cycles of heating, holding, and cooling, it was confirmed that the HEATMOS filter’s mechanical construction did not show any temporary or permanent deformation. Additional scan tests conducted after each cycle prove a repeated fulfilling and exceeding of the H14 rating in accordance with the EN1822 standard, therefore guaranteeing safety for the process at the currently highest level of filter efficiency for high temperature applications.

The confirmation of the mechanical stability of the HEATMOS filter in the arduous tests, steady H14 efficiency, absence of particle shedding, and easier handling, provide convincing arguments for its use in sterilization tunnels. 

Scan to read AAF International’s full whitepaper on the next step in filtration for dry heat sterilization applications.